2015 LEXUS RX450h brake sensor

2192-3. Operating the light s and windshield wipers
2
When driving Turning on the high beam headlights
With the headlights on, push the
lever away from you to turn on
the high beams. Pull the lever toward you to the
center position to turn the high
beams off.
Pull the lever toward you to turn
on the high beams. Release the lever to turn them off.
You can flash the high beams with
the headlights on or off.■
Daytime running light system ●
To make your vehicle more visible to other drivers, the daytime running lights
turn on automatically whenever the hybrid system is started and the parking
brake is released. Daytime running lights are not designed for use at night.
Type A: Daytime running lights can be turned off by operating the switch.●
Compared to turning on th e headlights, the daytime running light system offers
greater durability and consumes less electricity, so it can help improve fuel
economy.■
Headlight control sensor
The sensor may not function properly if an
object is placed on the sensor, or anything
that blocks the sensor is affixed to the wind-
shield.
Doing so interferes with the sensor detecting
the level of ambient light and may cause the
automatic headlight system to malfunction.

2402-4. Using other driving systems
Driving in vehicle-to-vehicle distance control mode
This mode employs a radar sensor to detect the presence of vehicles up
to approximately 400 ft. (120 m) ah ead, determines the current vehicle-
to-vehicle following distance, and op erates to maintain a suitable follow-
ing distance from the vehicle ahead. Note that vehicle-to-vehicle distance will close in when traveling on long
downhill slopes.
Example of constant speed cruising
When there are no vehicles ahead The vehicle travels at the speed set by the driver. The desired vehicle-to-vehi-
cle distance can also be set by operat ing the vehicle-to-vehicle distance con-
trol.
Example of deceleration cruising
When the vehicle ahead is driving slower than the set speed
When a vehicle is detected running ahead of you, the system automatically
decelerates your vehicle. When a grea ter reduction in vehicle speed is nec-
essary, the system applies the brakes. A warning tone warns you when the
system cannot decelerate sufficiently to prevent your vehicle from closing in
on the vehicle ahead.

2462-4. Using other driving systems
CAUTION■
Situations unsuitable for dynamic radar cruise control
Do not use dynamic radar cruise contro l in any of the following situations.
Doing so may result in inappropriate sp eed control and could cause an accident
resulting in death or serious injury. ●
In heavy traffic●
On roads with sharp bends●
On winding roads●
On slippery roads, such as thos e covered with rain, ice or snow●
On steep downhills, or where there are sudden changes between sharp up and
down gradients
Vehicle speed may exceed the set speed when driving down a steep hill.●
At entrances to expressways●
When weather conditions are bad enough that they may prevent the sensors
from functioning correctly (fog, sn ow, sandstorm, heavy rain, etc.)●
When an approach warning buzzer is heard often●
When your vehicle is towing a trailer or during emergency towing■
When the sensor may not be correctly detecting the vehicle ahead
Apply the brakes as necessary when any of the following types of vehicles are in
front of you.
As the sensor may not be able to correctly detect these types of vehicles, the
approach warning (  P. 241) will not be activated, and a fatal or serious accident
may result. ●
Vehicles that cut in suddenly●
Vehicles traveling at low speeds●
Vehicles that are not moving
●
Vehicles with small rear ends (tra ilers with no load on board etc.)
●
Motorcycles traveling in the same lane

2472-4. Using other driving systems
2
When driving CAUTION■
Conditions under which the vehicle-to-vehicle distance control may not function
correctly
Apply the brakes as necessary in the foll owing conditions as the radar sensor may
not be able to correctly detect vehicles ahead, and a fatal or serious accident may
result: ●
When water or snow thrown up by the surrounding vehicles hinders the function-
ing of the sensor●
When your vehicle is pointing upwards (caused by a heavy load in the luggage
compartment etc.)●
When the road curves or when the lanes are narrow●
When steering wheel operation or your position in the lane is unstable●
When the vehicle ahead of you decelerates suddenly■
Handling the radar sensor
Observe the following to ensure the cruise control system can function effectively.
Otherwise, the system may not function co rrectly and could result in an accident.●
Keep the sensor and grille cover clean at all times.
Clean the sensor and grille cover with a soft cloth so you do not mark or damage
them.●
Do not subject the sensor or surrounding area to a strong impact.
If the sensor moves even slightly off position, the system may malfunction. If the
sensor or surrounding area is subject to a strong impact, always have the area
inspected and adjusted by your Lexus dealer.●
Do not disassemble the sensor.●
Do not attach accessories or stickers to the sensor, grille cover or surrounding
area.
●
Do not modify or paint the sensor and grille cover.
●
Do not replace them with non-genuine parts.

2562-4. Using other driving systems
■
Sensor detection information ●
Certain vehicle conditions and the su rrounding environment may affect the
ability of a sensor to correctly detect an obstacle. Particular instances where this
may occur are listed below.
• There is dirt, snow or ice on a sensor.
• A sensor is frozen.
• A sensor is covered in any way.
• The vehicle is leaning considerably to one side.
• On an extremely bumpy road, on an incline, on gravel, or on grass
• The vicinity of the vehicle is noisy due to vehicle horns, motorcycle engines,
air brakes of large vehicles, or other loud noises producing ultrasonic waves.
• There is another vehicle equipped with parking assist sensor s in the vicinity.
• A sensor is coated with a sheet of spray or heavy rain.
• The vehicle is equipped with a fender pole or radio antenna.
• Towing eyelets are installed.
• A bumper or sensor receives a strong impact.
• The vehicle is approaching a tall or right-angled curb.
• In harsh sunlight or intense cold weather.
• A non-genuine Lexus suspension (low ered suspension, etc.) is installed.
In addition to the examples above, there are instances in which, because of their
shapes, signs and other objects may be judg ed by a sensor to be closer than they
are. ●
The shape of the obstacle may prevent a sensor from detecting it. Pay particular
attention to the following obstacles:
• Wires, fences, ropes, etc.
• Cotton, snow and other materi als that absorb sound waves
• Sharply-angled objects
•Low obstacles
• Tall obstacles with upper sections projec ting outwards in the direction of your
vehicle
■
If a message is displayed
 P. 74 3

2782-4. Using other driving systems
Pre-Collision System When the radar sensor detects the possib ility of a frontal collision, the pre-
collision system such as the brakes and seat belts are automatically
engaged to lessen impact as well as vehicle damage.
■ Pre-collision seat belts (front seat belts only) If the pre-collision sensor detects that a collision is unavoidable, the pre-
collision system will retract the seat belt before the collision occurs.
The same will happen if the driver makes an emergency braking or loses
control of the vehicle. (  P. 1 0 0 )
However, the system will not operate in the event of skidding when the
VSC system is disabled.
■ Pre-collision brake assist When there is a high possibility of a frontal collision, the system applies
greater braking force in relation to how strongly the brake pedal is
depressed. The system may not warn the driver using a warning light,
warning display and buzzer when the system detects and judges braking
operations.
■ Pre-collision braking When there is a high possibility of a frontal collision, the system warns the
driver using a warning light, warnin g display and buzzer. If the system
determines that a collision is unavoidable, the brakes are automatically
applied to reduce the collision speed. Pre-collision braking can be dis-
abled using the pre-collision braking off switch.
 : If equipped

2812-4. Using other driving systems
2
When driving ■
Conditions that may trigger the system even if there is no possibility of collision ●
When there is an object by the roadside at the entrance to a curve●
When passing an oncoming vehicle on a curve●
When driving over a narrow iron bridge●
When there is a metal object on the road surface●
When driving on an uneven road surface●
When passing an oncoming vehicle on a left-turn●
When your vehicle rapidly closes on the vehicle in front●
When a grade separation/interchange, sign, billboard, or other structure
appears to be directly in the vehicle's line of travel●
When climbing a steep hill causes an over head billboard or ot her metallic struc-
ture to appear directly in the vehicle's line of travel●
When an extreme change in vehicle height occurs●
When the axis of the radar is out of adjustment●
When passing through certain toll gates●
When driving on a bridge●
When passing through a tunnel
When the system is activated in the situations described above, there is also a possi-
bility that the seat belts will retract quickly and the brakes will be applied with a force
greater than normal. When the seat belt is locked in the retracted position, stop the
vehicle in a safe place, release the seat belt and refasten it.■
Obstacles not detected
The sensor cannot detect plastic obstacles such as traffic cones. There may also be
occasions when the sensor cannot detect pedestrians, animals, bicycles, motorcy-
cles, trees, or snowdrifts.

2852-4. Using other driving systems
2
When driving CAUTION■
When the sensor may not be correctly detecting the vehicle ahead
Apply the brakes as necessary in any of the following situations: ●
When water or snow thrown up by the surrounding vehicles hinders the function-
ing of the sensor●
When your vehicle is pointing upwards (caused by a heavy load in the luggage
compartment etc.)●
Vehicles that cut in suddenly●
Vehicles with small rear ends (tra ilers with no load on board etc.)●
Motorcycles traveling in the same lane■
Handling the radar sensor
Observe the following to ensure the pre-collision system can function effectively: ●
Keep the sensor and front grille clean at all times.
Clean the sensor and front grille with a so ft cloth so you do not mark or damage
them.●
Do not subject the sensor or surrounding area to a strong impact.
If the sensor moves even slightly off po sition, the system may become inaccurate
or malfunction. If the sensor or surround ing area is subject to a strong impact,
always have the area inspected an d adjusted by your Lexus dealer.●
Do not disassemble the sensor.●
Do not attach accessories or stickers to the sensor, grille or surrounding area.●
Do not modify or paint the sensor and grille cover.